The present invention relates to a method and apparatus for shredding a block of material, such as a moldable, plasticized product and, in particular, to a method and apparatus for forming shreds of a food product, such as cheese. The present invention is particularly useful for forming shreds from relatively long or continuous blocks of material, such as cheese.
Although the following description is focused on forming shreds from a block of cheese, it will be recognized by those skilled in the art that the present invention encompasses forming shreds from a block of any suitable material. As used herein, the term xe2x80x9cshreddingxe2x80x9d refers to the process of shredding a block of material into shreds or slicing a block of material into smaller pieces.
Traditionally, machines for shredding cheese have been designed to cut non-continuous, blocks of cheese. For example, one known method of shredding cheese takes large blocks of cheese, typically having a height of about 7 inches, a width of about 11 inches, and a length of about 14 inches, and cuts up the large blocks of cheese into small, finite cubes of cheese having a height of about 1 inch, a width of about 1 inch, and a length of about 1 inch. The cubes of cheese are then shredded using a centrifugal shredder, such as the Model CC shredder manufactured by Urschel Laboratories, Inc, of Valparaiso, Ind. (the xe2x80x9cUrschel shredderxe2x80x9d). In the Urschel shredder, the cubes of cheese are dropped into a stationary cylindrical chamber housing a series of blades. The cylindrical chamber is positioned around a rotating plate having a series of impellers. The blades are lined up against the wall of the cylinder. The centrifugal force caused by the rotating plate moves the cubes of cheese from the center of the rotating plate out towards the edges of the rotating plate. As the cubes of cheese approach the edges of the rotating plate, the cubes of cheese are pressed up against the wall of the cylinder and the series of impellers drag the cubes of cheese across the wall and past the blades, resulting in the cutting of the cubes of cheese.
Such conventional shredders have some disadvantages. Centrifugal shredders use a considerable amount of energy in cutting the cubes of cheese, since the cheese must be moved across the rotating plate, pressed firmly against the wall of the cylinder, and dragged across the wall and past the blades in order to cut the cheese. Moreover, the large blocks of cheese must be formed and then cut into small cubes of cheese in order to use a centrifugal shredder.
Another known method of shredding cheese is to take long, narrow blocks of cheese, typically having a height of about 3.5 inches, a width of about 5.5 inches, and a length of about 14.0 inches, and use a cheese shredder having a cutting disc to cut the long, narrow blocks of cheese. The cutting disc rotates about an axis parallel to the length of the block of cheese. Such a cheese shredder is manufactured by Hobart Manufacturing Co. of Troy, Ohio (the xe2x80x9cHobart shredderxe2x80x9d). In this arrangement, the long, narrow blocks of cheese are pressed up against the cutting disc which is comprised of a series of blades. As the cutting disc rotates, the long, narrow blocks of cheese are cut. In order to shred cheese with such a device having a cutting disc, the cheese must be formed into long, narrow blocks of cheese before the cheese can be shredded.
It is also known that certain manufacturing processes produce products that are not as easily shredded as products produced by other processes. For example, in one known process, cheese is melted and extruded into a thin sheet upon a surface such as a moving belt. In this process, molten cheese is fed into a manifold, which distributes the molten cheese in a layer onto a continuously moving endless belt, which is commonly called a casting belt. Such a process, and the apparatus used in such a process, is described, for example, in U.S. Pat. Nos. 5,527,551 and 5,573,805. The thin, continuous sheet of cheese may have a width of about 36 inches, for example. The thin sheet may then be cut along its width to form a plurality of thin ribbons, and then the plurality of thin ribbons may be stacked on top of each other to form continuous, stacked ribbons of cheese. The stacked ribbons of cheese form or define a continuous block of cheese (i.e., a block formed from the stack of ribbons). Although processing the cheese to form a continuous block in the manner described above provides significant manufacturing advantages, conventional shredders such as the centrifugal shredders are not designed to handle stacked ribbons of cheese. Rather, such shredders are designed to handle finite cubes of cheese. The stacked ribbons of cheese formed by the casting belt arrangement are typically too thin to be shred by a centrifugal shredder.
Another known shredder is disclosed in U.S. Pat. No. 5,601,855. In the shredding device disclosed in this patent, a continuous sheet of cheese from a casting belt is shred by a comb-like arrangement. The sheet is fed in a feed direction to a rotating comb with fingers that extend radially outward. The fingers sheer the thin sheet of cheese into shreds. At the point of contact between the fingers and the sheet of cheese, the fingers of the comb are substantially parallel with the sheet and extend in the feed direction. Thus, the shreds are formed from the sheet such that the length of each shred is parallel to the feed direction. One disadvantage of this arrangement is that the shreds have a uniform, substantially rectangular configuration. The shape of the shreds is dictated by the fingers in the comb. There is little ability to change the shape of the shreds. It has been found that the consumer, however, prefers a more traditional looking shred of cheese. Traditional shreds of cheese have a more feathered look. The feathered look is provided by the blade geometry and by shredding a block, instead of a sheet, of cheese.
Cheese shredders of the cutting disc-type are also not designed to cut stacked ribbons of cheese. Such cutting disc-type shredders used on a stack would result in unacceptable sizes and shapes for the shreds. The reason is that the path of the cutter does not follow the plane of the ribbons. As the blade in cutting disc-type shredders rotate, shreds would be formed in an arc across the face of the ribbons.
Therefore, a number of characteristics are desirable for an apparatus to efficiently cut ribbons of cheese, such as a block formed from continuous, stacked ribbons of cheese. Preferably, the apparatus cuts the cheese using less energy than traditional methods.
In view of the above limitations of existing cheese shredders, it is an aspect of the present invention to provide an apparatus for shredding a block of a material, such as cheese. The apparatus comprises a cutting unit having a cutting blade. The cutting blade is arranged to rotate about an axis. A feed unit moves the block of material in a feed direction toward the cutting unit. The feed direction is generally perpendicular to the axis about which the cutting edge rotates. Shreds of cheese are cut from the block such that the length of the shreds lies along the face of the block.
In one preferred embodiment, the block of material comprises a plurality of ribbons, wherein the ribbons are stacked atop each other. In one preferred embodiment, the cutting blade comprises a serrated blade having a plurality of teeth, and the distance between the teeth is less than the thickness of each ribbon.
Another aspect of the present invention is a method for shredding a block of material, the method comprising moving the block of material in a feed direction toward a cutting unit. The cutting unit has at least one cutting blade. The cutting blade is rotated about an axis that is generally perpendicular to the feed direction such that as the block of material reaches the cutting blade, the cutting blade moves across the face of the block and shreds the material across the face of the block.
In yet another aspect of the invention, an apparatus for shredding a block of material includes a shredding unit having a plurality of blades on a rotatably driven drum, the drum rotating about a substantially vertical axis. A drive unit rotates the drum about the axis. A feed unit moves the block of material on a feed plane toward the shredding unit in a feeding direction, the feed unit being disposed upstream of the shredding unit, and the feeding direction being substantially perpendicular to the substantially vertical axis about which the drum rotates. In operation, the plurality of blades cut shreds of material from a front face of the block.